I. Field of the Invention
This invention relates generally to the treatment of urinary incontinence. More specifically, this invention relates to our improved sling that can be surgically implanted to support the urethra and bladder neck to mitigate the involuntary discharge of urine from the bladder.
II. Description of the Prior Art
Urinary incontinence is a common problem, especially in women. It is estimated that there are over 13 million individuals with urinary incontinence in the United States, of which about 85% are women. Stress urinary continence is a condition in which the patient leaks urine when a sudden increase in his or her abdominal pressure occurs. This increase in abdominal pressure can result from many routine daily activities such as laughing, sneezing, walking, or getting up from a chair. The increase in abdominal pressure causes an increase in pressure in the bladder. When the pressure in the bladder is sufficiently great to overcome urethral sphincter leakage will occur.
Various treatments have been provided for stress urinary incontinence. For over 100 years, surgeons have used sub-urethral sling procedures to treat severe or refractory genuine stress incontinence. This preprocedure, sometimes referred to as pubovaginal sling procedure, is used to treat urinary stress incontinence by creating a support to the urethra and bladder neck complex. Providing this support serves to increase the urethral closure pressure during stress to mitigate the involuntary loss of urine. In this surgical procedure, a sling hanging from and secured to the pubo-abdominal side is used to support the urethra from below.
Traditionally the materials used to create the sling include excised native retus fascia and fascia lata from the patient. More recently, chemically treated cadaveric fascia lata has been used. Some synthetic materials have also been used. These included woven sheets made of polypropylene, Dacron, and other flexible but non-elastic material. Synthetic slings have also been coated with collagen products, such as Protegen, which is marketed by Boston Scientific Corporation. Protegen is a rigid woven material coated with collagen which is intended to provide faster or better tissue integration into the sling material.
Though the pubovaginal sling procedures have been effective in returning continence to women, there is a common and persistent problem of high rates of prolonged urinary retention after surgery. This problem often requires the patients to perform self-catheterization and can also lead to secondary detrusor instability. Various techniques have been devised in an effort to overcome such problems. These techniques generally allow the final ligature a substantial amount of free-play by adjusting the sling tension to reduce urinary retention and provide continence. However, these techniques require great skill and increase the difficulty of an otherwise very effective surgical procedure.